OAuth W. Denniss
Internet-Draft Google
Intended status: Standards Track S. Myrseth
Expires: September 4, 2016 ForgeRock
J. Bradley
Ping Identity
M. Jones
Microsoft
H. Tschofenig
ARM Limited
March 3, 2016
OAuth 2.0 Device Flowdraft-ietf-oauth-device-flow-01
Abstract
The device flow is suitable for OAuth 2.0 clients executing on
devices that do not have an easy data-entry method (e.g., game
consoles, TVs, picture frames, and media hubs), but where the end-
user has separate access to a user-agent on another computer or
device (e.g., desktop computer, a laptop, a smart phone, or a
tablet).
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 4, 2016.
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Internet-Draft OAuth 2.0 Device Flow March 2016
(E) While the end-user authorizes (or denies) the client's request
(D), the client repeatedly polls the authorization server to find
out if the end-user completed the end-user authorization step.
The client includes the verification code and its client
identifier.
(F) Assuming the end-user granted access, the authorization server
validates the verification code provided by the client and
responds back with the access token.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
[RFC2119].
Device Endpoint:
The authorization server's endpoint capable of issuing
verification codes, user codes, and verification URLs.
Device Verification Code:
A short-lived token representing an authorization session.
End-User Verification Code:
A short-lived token which the device displays to the end user, is
entered by the end-user on the authorization sever, and is thus
used to bind the device to the end-user.
3. Specification3.1. Client Requests Authorization
The client initiates the flow by requesting a set of verification
codes from the authorization server by making an HTTP "POST" request
to the device endpoint. The client constructs a request URI by
adding the following parameters to the request:
response_type:
REQUIRED. The parameter value MUST be set to "device_code".
client_id:
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Internet-Draft OAuth 2.0 Device Flow March 2016
REQUIRED. The client identifier as described in Section 2.2 of
[RFC6749].
scope:
OPTIONAL. The scope of the access request as described by
Section 3.3 of [RFC6749].
For example, the client makes the following HTTPS request (line
breaks are for display purposes only):
POST /token HTTP/1.1
Host: server.example.com
Content-Type: application/x-www-form-urlencoded
response_type=device_code&client_id=s6BhdRkqt3
In response, the authorization server generates a verification code
and an end-user code and includes them in the HTTP response body
using the "application/json" format with a 200 status code (OK). The
response contains the following parameters:
device_code
REQUIRED. The verification code.
user_code
REQUIRED. The end-user verification code.
verification_uri
REQUIRED. The end-user verification URI on the authorization
server. The URI should be short and easy to remember as end-
users will be asked to manually type it into their user-agent.
expires_in
OPTIONAL. The duration in seconds of the verification code
lifetime.
interval
OPTIONAL. The minimum amount of time in seconds that the client
SHOULD wait between polling requests to the token endpoint.
For example:
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HTTP/1.1 200 OK
Content-Type: application/json
Cache-Control: no-store
{
"device_code":"74tq5miHKB",
"user_code":"94248",
"verification_uri":"http://www.example.com/device",
"interval"=5
}
The client displays the end-user code and the end-user verification
URI to the end-user, and instructs the end-user to visit the URI
using a user-agent and enter the end-user code.
The end-user manually types the provided verification URI and
authenticates with the authorization server. The authorization
server prompts the end-user to authorize the client's request by
entering the end-user code provided by the client. Once the end-user
approves or denies the request, the authorization server informs the
end-user to return to the device for further instructions.
3.2. Client Requests Access Token
Since the client is unable to receive incoming requests from the
authorization server, it polls the authorization server repeatedly
until the end-user grants or denies the request, or the verification
code expires.
The client makes the following request at an arbitrary but reasonable
interval which MUST NOT exceed the minimum interval rate provided by
the authorization server (if present via the "interval" parameter).
Alternatively, the client MAY provide a user interface for the end-
user to manually inform it when authorization was granted.
The client requests an access token by making an HTTP "POST" request
to the token endpoint as described in Section 4.1.1 of [RFC6749] .
The "redirect_uri" parameter is NOT REQUIRED as part of this request.
3.3. Additional Error Responses
The following error responses are defined in addition to those within
Section 4.2.2.1. of [RFC6749]:
authorization_pending
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Internet-Draft OAuth 2.0 Device Flow March 2016
The authorization request is still pending as the end-user hasn't
yet visited the authorization server and entered their
verification code.
slow_down
The client is polling too quickly and should back off at a
reasonable rate.
4. Security Considerations
TBD
5. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC6749] Hardt, D., Ed., "The OAuth 2.0 Authorization Framework",
RFC 6749, DOI 10.17487/RFC6749, October 2012,
<http://www.rfc-editor.org/info/rfc6749>.
Appendix A. Acknowledgements
The -00 version of this document was based on draft-recordon-oauth-v2-device edited by David Recordon and Brent Goldman. The content of
that document was initially part of the OAuth 2.0 protocol
specification but was later removed due to the lack of sufficient
deployment expertise at that time. We would therefore also like to
thank the OAuth working group for their work on the initial content
of this specification through 2010.
Appendix B. Document History
[[ to be removed by the RFC Editor before publication as an RFC ]]
-01
o Applied spelling and grammar corrections and added the Document
History appendix.
-00
o Initial working group draft based on draft-recordon-oauth-v2-device.
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